Electropneumatic brake



Dec. 20, 1927. `1,653,133

T. H. THOMAS ELECTROPNEUMATIC BRAKE Filed Feb. 23. 1927 Figi.

x lum lum ATTORNEY Patented Dec. 20,k 1927.

UNiTEo l STATES.

j 1,653,133 PATENT orrice.

'r-HonIAs n'. THOMAS, on EDGEWQOD, PENNSYLVANIA, AtSSIGNQR TQ J1EE WE,Sfr-Elli@-v HOUsE AIR BRAKE GoMBANYtF WILMERDING. PENNSYLVANIA, A CORBORATION OF PENNSYLVANIA.

ELEQTROPNEUMATIQ BRAKE.

. Application inea4 February. 2a, 1927; serial No. 170,972.

This invention relates to electro-pneumatic brakes and more particularly -to a brake equipment for` electrically controlling the brakes on a. locomotive and: carsin a train.

The principalobj'ect of" my invention is to provide an improved electro-pneumatic brake equipment of 'the type in which the brakes are controlled current flow through a single train Wire.

In the accompanying drawing; Fig, 1 is a diagrammatic view of; anv electrically controlled brake equipment embodying my inn vention; and Fig; 2' is a sectional, diagramv matic view of the, pneumatic equipment employed on the locomotive and` each car in the train,l arnd having `associated therewith the electric controlling means. c

As shown in Fig. 1 of the drawing, the electric equipment'uon the locomotive 'comprises a brake switch device 1, a battery or other source of: direct current supply 2, a rheostat device 3, and an ammeter 4. The locomotive and each car of the train are equipped with magnet val-ve devices 5- and r 6 and a rectifier-device@ all connected toa single train wire 14.

As shown in Fig.g2I of the drawing, the magnet valve devices 5 and 6 are employed in connection with apneumaticvalve device, which may' comprise a triple valve portion 8,-a selector valveportion- 9, vappipe bracket 10, a` brake cylinder 11, and an auxiliary reservoir l2. i i The brake switch device 1f, shown, in de-r velolpment` form in Fig. Al, may comprise a contact drum, adapted to bey rotated through the various positionsy to effectthe electrical connections yshown for, each position and is adapted to be operated independently,while the usual automatic brake valve device remains in the running position.

The rheostat device 3 may comprise lthe usual resistance coils and a contact arm 13V valve 42.

Connectedv i'nparallel'to the train wire are the magnet* valve devices 51 andv 6 on` the locomotive and each car.; f

'I lhe magnet valve device "5^ comprises a" casing containing a magnet and having a chamber 17' containing a valve 18, saidy valve having a fluted stem extendingy 'through a bore in 'the wall of' the casing and: engaging in chamber 19 the stem ofa valve 2O- con- `i tained in chamber 2 1. Also contained in chamber'21 isa collared stem 22, heldin en-` gagement with the valve '20-*by the pressure of a spring 23, against the collarostem 22;

The-magnet valve device 6' comprises a magnet and has. a chamber 24 containing a double beat valve 25. The upper valve has a flutedstemextending through a chamber 26, which is connected to thev atmosphere through passage 27 while the lower valve has af luted stem extending into -avchamber 28 and engaging the; collar of a stem 29, acted* upon by the pressure of a spring 30;' The winding of the coil in the magnet 5 is such thatA itwill become,r energized; to oper*- ate the 'valves18- and 20l on-a lower current How than is required" in the magnet 6" to operate, theV valve 25. i y "'Interpos'ed in the circuit only with each magnet val-ve device 5 is agrectier device 7, adapted toypermit the flow of current only in one direction, as is indicated by the arrowon the device. The pipebracket 10has .two faces, against which lthe triple, valve device 8 and" selector valve device portion 9 are secured, and2 connected to, passages in said' bracket are the usual brakefcylilnder 1,1 and thev auxiliary reservoir l2'.

` The triple valve device :8 comprises a casing havin ,a iston chamber 31v connected to t e brake pipe32 and containing a piston 33, anda valve chamber 34 connected tlirough'passage to the auxiliary reserf c f voir 12 and containing a main slide valve 36 and an auxiliary slide valve 37,l adapted to be, operatedby ysaid piston.

- The triple valve also. hasva quick action. portion, comprising a quickact-ion portion 38, contained chamber 39, anda chamber noy 40v containing a brake pipe vent valve 4:1,

adapted to vbeioperated by said piston. Also contained in chamber `40A is the usual' check The selector valve port-ion comprises a casing having a bracket on which the magnet valve devices 5 and 6 are mounted and having a piston chamber 43 connected through passage 44 to the double beat valve chamber 24 and containing a piston 45 and a spring 46 acting on said piston, and a valve cham-r ber 47 connected through passages 48 and 49 to valve chamber 84 of the triple valve de-` vice and containing a slide valve 50 adapted to be operated by said pistonf" In operation, the fluid pressure brake system is charged in the usual manner and lluid from the brake pipe 32 flows to piston 'chamber 3l and thence hrough kthe feed groove 5l to the valve chamber 34 and through passage 35 to the auxiliary reservoir i l2, charging said chamber and reservoir.v

Fluid at auxiliary` reservoir` pressure in valve chamber 34 is supplied through passages 49 and 4S to the selector valve `chamber 47 and from passage 48 through passage 52 to the spring chambers 2l and 28 oic the magnet valve devices 5 and 6, respectively. A

The rheostat 3 is adjusted to permit the predetermined required c degree current iiow in the train wire, as determined by the train length and as Hindicated by the ammeter 4. i l lVith the brake switch l in the combined release and running position, the train wire 14 is connected through the rheostat 3, the ainmeter 4 and wire 53 to the contact 54 on the brake switch drum, and thence tl rough wire 55, contact 56, and wire 57, to the ter-r minal 58 ol the battery The circuit is then completed through the negative pole i 59 of the-battery, Wire 60, `drum contact 6l,

Wire 62 and the ground 63 onthe locomotive. Thetrain wire 14 is grounded at 16 at the end of the train. i 'i Under these conditions, onlyV a portiono" i the battery is cut into the circuit, and with the' positive pole connected through the brake switch to the train wire 14, thecurrent flows throughthe rectilier devices 'i' and the magnets 5, energizing said magnets. The

current strength, underthese conditions, is

insuiicient to cause the magnets 6 to operate anfl shii't the double heat valve 25 to( the lower position,

lWiththe double beat valve 25 in its upper position, thereby closing communication between chambers 24 and26 and opening communication between ychambers 26 and 24, fluid under pressure in -chamber 2S is permitted to flow through chamber 24 and passage 44 to the selector piston chamber 43. The fluid pressures then equalize on opposite sides of the selector piston 45,.,so that the pressure otspring 46 holds said piston nid slide valve 50 in the upper or release position, as shown in the drawing. f i y The magnet 5 being energized7 operates to seat the valve` 18 and unseat the valve 20,

which permits the tlow oit iuid under pressure trom chamber 2l, through chamber 19 to passage 6 4 and thence through pipe 65 to the reservoir 66, charging said reservoir to the pressure in the selector' valve chamber 4i". assage'64 also leads to the seat of the selectory slide valve 50, but is lapped in release position or' the slide valve.

lilith theselector piston 45 and slide valve 5() in release position, the brake cylinder 'll is vented to the atmosphere by way of passages 6T and 68, past the ball check valve 69, through vpassage 70, cavity 7l in the triple valve slide valve 36, passage 72, cavity T3 in the selector slide valve 50 and to the atmospheric exhaust port 74,V To eti'eet a service pplication oit the` brakes, the brake switch device 1 is turned to service position, in which a circuit is completed from the train wire i4, through the rheostat 3, ammeter 4, wirev brale drum contact 93, wir@ S6, Contact 87 and Wire 60 tothe negative pole 59 of the battery 2, through the battery` to the positive pole 88, wire 89, contact 90 on thev drum, wire 91, contact and wire 62 to the ground 63, the train wire 14 at the rear of the train being grounded at 16. 'Current Ytroni the full battery is thus supplied to the train wirel4 and is suflicient to energize the magnets 6. Since the negative pole 59 of the battery 2 is connected through the brake switch `l to the train wire. 14, the direction or' current flow .is opposite to that permitted through the rectier 7, as indicated by the arrows, so thatinagnets 5 are deenergized. Energizationot the magnet 6 operates to shift the double beat valve 25 to its lower position and close communication between chambers 24 and 28 and connect chamber 28 t: chamber 26 and thus passage27 to the atmosphere. Chamber 24 being connected through passage 44 to the selector piston chamber 46, thexiiuid underpressure in said chamber is vented to the atmosphere` which permits-the higher pressure in valve chamber 47 to shift the piston 45 and slide valve 5()k to the lower-'or service` position, in which the brake cylinder' passage 72 is lappedby 'the slide 'valve 50, and the `passage 64 Ais uncovered by said slide valve, and thus ,conneet-ed to the chamber 47. 1 The magnet 5 being deenergized, the pres.-` sure ot spri 23 seats the valve 2O and lunseats the valveA 16, whiclrpermits fluid at aiiirliliary f reservoir pressure in the triple valve slide `valve chamber 34 to flow to thev bralre cylinder ll by way ot passages 4S) and4f-l, selector slide valve chamber 4T, passage 64. chamber i9, past Vthe valve 18, chamber l?, passafgefi, past theball check `alve 76,\through passage 77, cavity T8 in the selector slide valve 50, passages T9, T0., 6,8"and6', thereby applying the brakes.

li"- it is desired to limit the degree oit brake neueres permit` I'loW of current through the rectifier' 7 to the magnet 5; f f

The full battery'l Current being? sufficient to energize the magnet 6, both magnets 5 and 6 are energized in lap position. y

The magnet 6 being energized maintains thefdouble beat valvej 25 inlv thelower-.position, thereby connecting the selector piston chamber 43 to the atmosphere and holdingv said piston 'andf slide valve 50 inthe lower or application position. Y f

Energization ofthe magnet 5 operates to unseat the valve 2OV andy seat thevalve 18,

' soy as to prevent furtherlflovv oit'- fluid `under asfWillbe'evident 1- pressure from chamber 19 through chamber- 17 and to the brake cylinder 11', as hereinbefore described'. Therefore, with the brake switch in lap positiom the brake cylinder pressure .Will neither be increased "nor decreased. f f

By alternately moving. the brakeA switch between service and lap positions, the brake cylinder pressure may be increased in steps,

To release an application ofthe brakes, the brake switch 1 is turned to .the vrelease and running` position, in which the magnets 5 becomes energized, but the magnets 6 remain in the deenergized position, as hereinbefore described.

Energization of the magnet 5 unseats the valve 20 and seats the valve 18, so as to prevent further flow of fluid under pressure from chamber 19 to chamber 17 and thence to the brake cylinder. The magnet 6 being in the deenergized position, the pressure of spring 30 seats the double beat valve 25 in its upper positionin which fluid under pressure is permitted to flow from chamber 28 through chamber 24 and passage 44 to the selector piston chamber 43 and equalize with `the pressure of the fluid in the selector valve chamber 47. lVhen the pressures become equal on opposite sides of the selector piston, the pressure of spring 46 shifts said piston and slide valve 50 tothe upper or release osition, in Which the brake cylinder passagel r2 is connected to the atmosphere through cavity 73 and the exhaust passage 74, thereby e permitting a release of the brakes.

If it is desired toi graduate the release of the brake cylinder pressure, the brake switch 1 is moved from the release and running Vpassage 67 to the brake cylinder 11.

position 'to lap position,` When'fthe'. desiredI decrease in brake cylinderv pressure' isV obvw tained.

- Inlap position, thema'gnet remains energized Whileathe magnet 6. also becomesener gizedy and; operates to vent.' fluid fromgthc selector pistonchambertS/to the atmosphere, so that thek selector piston and slide valve are then shifted. downwardly to application'y position', in which the brake cylinder passage 72` is:` lapped byl the selector slide valve 50, thereby' preventing awfurtlier decrease inthe pressure of the brake cylinder-fluid'.

- Thus to'secure a graduated releaseof the brakes-the brake sWit-chmay .be alternately moved from releaseand running position. to lap position, as will be'evident.

yTo effect an emergency application of theA brakes, the brake Vswitch l isturnedxto emergencyA position, in Whichvthe train Wirev circuit is broken, thereby causing both magnets 5 and 6 to be deenergized. f

The p magnet 6` being` deenergized, the double beat valve 25 is in: its upper position", so that vfluid under pressureissupplied to the selector piston chamber, thereby permitting the spring46 to hold the selector piston 45 and slidevalve 50 in release position The magnet 5 lbeing deenergized, the valve 20 is seated and the valve 18- is unseated,so that the fluid under pressure: in the reservoir 66 isf supplied to thequick action pistonBS by way of. pipe 65,. passage 64, chamber 19, past valve 18, chamber 17, passage 7 5,*past ball check valve 7 6, passage 77, cavity 78 in the selector slide valve 50, and passage. 83 tothe quick action piston chamber 39;

` #The quick actionl piston 3,8 is therebyoperatedto openthe: brake pipe vent val-ve41 and vent the fluid under `pressure in cham" ber 40 into chamber 84 and thence through The pressure of the fluid in the brake pipe 32 thenv being higher than the pressure in chamber 40 lifts the check valve 42, and said fluid then flows through chambers 4() and 84 to the brake cylinder and thus causes a sudden local drop in brake pipe pressure, which causes the triple valve piston 33 and slide valves 36 and 37 to be shifted to emergency position. .In emergency position, port 85 in the main slide valve, 36 registers with the brake cylinder passage 70, so that fluid under cause or thetrain wire should become broken,

an emergency application of the kbrakes will be automatically effected in the same manner as above described irrespective of the po: sition of the brake switch l.

Vhen an electric service application of the brakes is eilected, the fluid under pressure employed to apply the brakes is taken from the triple valve chamber 34 and auxiliary reservoir l2 by Way of passage 49. The usual automatic brake valve device being normally in running position during electric operation, permits the maintenance of brake pipe pressure at the adjustment of the feed valve device. Therefore, although the pressure in the valve chamber 34 and the auxiliary reservoir 12 tends to be reduced, the pressure in the auxiliary reservoir is substantially `maintained by flow from the brake pipe through the usual feed groove 5l, around the piston 33.

If a car equipped with the above described appara-tus is placed in a train not provided With electric control, the magnets 5 and 6 will both be deenergized, so that the valve 2O will be seated, cutting ott the supply of tluid from the brake pipe to the reservoir 66, While thevalve 18 vvill be opened, and luid in said reservoir will be vented to chamber 39 above the quick action piston 38 and thence to the brake cylinder in the usual manner.

Since there is no fluid pressure in the reservoir 66 under the above conditions, there Will be no action of the electric portion, and the equipment of the train Will act only pneumatically in the usual manner.

Having noW described my invention, What I claim as new and desire to secure by Letters Patent, is

l. In an electrically controlled brake, the combination with a single train Wire, of groups of electrically controlled devices for controlling the brakes, `th'e devices of each group being connected in parallel with said train Wire and the groups being connected in series in said Wire.

2. In an electrically controlled brake, the combination with a single train Wire, of pairs of electrically controlled devices for controlling the brakes, the devices of each pair being connected in parallel with said train Wire and the pairs of devices being connected in series in said Wire.

3. In an electricallycontrolled brake, the combination With a single train Wire, of pairs of electrically controlled devices for controlling the brakes, `means in circuit with one device of each pair for preventing flow of current through said device in one direction, the devices of each pair being connected inparallel withV said train Wire and the pairs of devices being connected in series in said Wire.

4. In an electrically controlled brake, the combination with a single train Wire, of pairs ot electrically controlled devices for controlling the brakes, means in circuit with one device of each pair for preventing flow of current through saidV device in one direction, the devices of each pair being connected in parallel with said train Wire and the pairs of devices being connected in series in said Wire, means for supplying current to said train Wire in either direction of flow, and means for regulating the rate of current flow to provide the same current flow regardless of the length of the train.

In testimony whereof I have hereunto set my hand.l

THMAs H. THOMAS. 

